He compares a cordless mouse to a hand axe from the Middle Stone Age. While the invention of the hand axe went roughly unchanged for millions of years, the similarly-shaped computer device, which will be outdated and discontinued in just a few years, represents something far more impressive.

The hand axe is intuitive -- the concept is easy to grasp. The mouse, however, goes over most peoples' heads; it's not an easy idea to communicate or conceive. An invention like the mouse is only possible with collaboration.

"When we moved away from self-sufficiency and began to work together, combining our knowledge, the consequence was far-reaching: We created things we could not and do not understand, from cordless mice to urban metropolises,' says Ridley.

He writes that the key to human invention is the exchanging of ideas and efforts. Think of all the employees it takes to run one company. The sum is greater than all of the parts.

In this way, innovation is like sexual reproduction and natural selection. "In asexual species," Ridley writes, "wholly different mutations that arise in different lineages cannot be combined. They compete with one another, and whichever one most enhances the individual’s survival and ability to reproduce survives at the expense of the others. In sexual species, mutations can join the same genomic team, because of genetic exchange. Sex makes evolution cumulative." Just as the merging of species leads to evolution (apes to man-kind), joining ideas takes creativity to unthinkable heights.

Thanks to the Internet, the sharing of ideas is easier and faster than ever. According to Stanford economist Paul Romer, "There is not a theoretical limit to the number of combinations of atoms and electrons we can devise, and the rate at which we devise them is bound to accelerate." It's all thanks to collaborative innovation.